Antioxidant Activity and Phenolic Content of Campomanesia Phaea Extracts Obtained by Pressurized Liquid Extraction

Abstract

Objective:This research used the Pressurized Liquid Extraction process (PLE) to obtain cambuci extracts rich in phenolic compounds and, consequently, with high antioxidant activity. Methods:We determined the centesimal composition and the mean particle size of the dried and crushed sample for characterization of the fixed bed extractor. Extractions with pressurized ethanol were performed following a Central Composite Design (CCD) with temperature (60 °C at the center point with ± 10 °C amplitude) and the contact time between the solvent and the matrix (6 min at the center point with ± 2 min amplitude) as independent variables in the process. The Total Phenolic Content (TPC) of compounds and antioxidant activity were determined. Results:The mean particle size of the cambuci in the PLE was 263.4 μm with apparent and real densities of 32.42 g/cm 3 and 1.62 g/cm 3 , respectively, resulting in a fixed bed porosity of 0.43. The centesimal composition of the comminuted and dried sample was 12.5 ± 0.1% moisture, 3.2 ± 0.2% ash, 3.35 ± 0.07% crude protein, 10.32 ± 0.08% crude fiber and 0.35 ± 0.04% ethereal extract. The highest extraction yield (41.7%) was obtained by using the binomial 70 ºC with 8 min of solvent contact in three batches. Extracts with the highest TPC (6501.10 mg AGE/100 g sample) were obtained by the binomial 74 °C with 6 min of contact; the binomial 50 °C with 4 min of contact gave rise to the extract with the highest antioxidant activity. The CCD showed high yield extracts with high antioxidant activity and a high total phenolic compound content. Conclusion:With the use of the proposed experimental design, it was possible to optimize the extraction of total phenolic compounds from the sample.